Electrical apparatus



o. H. ESCHHGLZ ELECTRICAL APPARATUS Filed May 26, 1925 HNVENTGR WWNASESZ Patented Dea 29, 1925.

-UNITEDsfr- A'ri-s PATENT A'ori-ica OTT- H. ESCIHHOLZ, OFSBUBG, PENNSYLVANIA, ASSIGNOR TO WESTINGHOUSE ELECTRIC & MANUFACTURING (OMEANY', A ('JOABIOBA'JJION 0F PENNSYLVANIA..A

ELECTRICAL AIEZEABA'ILUIS.I

' Application mea rayas; 192:,...A serial no.' 841,620.

To all whom it may' concern:

Be it known that I, O'i'ro H.`EsoHHoLz, a citizenof the United States, and a resident of Wilkinsbur in the county of Alle- 6 gheny and State o Pennsylvania, have invented a new and useful Im rovement in y Electrical Apparatus, ofwhic .the following is a specification. 1.

` My invention relates to electrical" appara- 10v tus, and it has particular relation `to casings or tanks for transformers,circuit breakers or other electrical devices.-

f My invention has, for one of its objects, to

provide means whereby inert gases isolated from the atmosphere within a casing ontank forelectrical apparatus may expand or contract within certain limits and whereby the gaseous contents may escape into the atmos- .phere only upon the occurrence of a predetermined maximum pressure.' i

-, A second object of my invention 1s to provide 'simple and eliicient meanswhereby the pressure of gases within closed casings is maintained substantially constant within a predetermined range of temperatures and whereby access to the atmosphere-is provided upon the occurrence of excessive pressure.

A further objectof my invention is to provide simple means for preventing oil or other insulating fluid from being ejected from a casing for electrical apparatus in i, case of sudden increase of pressure or production of gases therein. r 85 A still further object of my invention is to provide means wherebythe'air-tight seal betweenthe mainbody and the cover of a tank for oil-immersed devices is protected by limiting the pressure` to which it' may be 40 subjected under normal operating conditions.

and underabnormal conditions.

In the o eration of transformers, -it` has been' found) blanket of inert gas over the oil for insulating the apparatusfin order to reduce the danger from exploslons .of hydrocarbon gases. Inasmuch'as a deoxidizinfr material is employed to roduce and mamtain the inert gas, prefera l nitrogen, itis desirable also, to minimize t e exchange between the such, for example, as nitrogen.

to be desirable to maintain al gaseous contents of the tanks and the `atmosphare in order to material.,

' In View of the fact that short circuits may cause' arcs within the apparatus and' that gases may-be produced' thereby in relatively conserve .the deoxidizing largel quantities cwith a'resultant sudden in- 'crease in pressure, it is desirable to provide means for, relieving excessive pressure, and, at the same tim-e, to prevent the escapeo oil from the tank.

In accordance with the present invention,

4I provide a gasometer on the tank to permit variations in'volume ofthe gas without contact with the atmosphere.4 Relatively thin portions of the gasometer walls yield at predetermined pressures, while4 suitable bullies are provided to prevent the escape of .oil from the tank in case of its agitation by arcs under its surface.

In the accompanvin figure is a longitudinali sectional'view of a casing for electrical apparatus constructed in accordance with my invention.

A casing 1, which mav be for example, a

transformer casing, is provi ed with a cover l2 that is attached to the main portionv of thecasin in an air-tight manner. The casing may e partially filled withfoil or other suitable insulating liuid, indicated at 3. The

drawing, the single space 4 abovethe oil is occupied by inert gas,

. Upon the cover 2 is. mounted a gasometerl Ilfof the type comprising an annular con-l tainer l2 for liquid which constitutes a seal for a' movable membervl. Communication between the casing 1 and the gasometer 11 is provided by a pipe 14 which contains a plurality of baille members 15. The bathe members are inclined downwardly and are in staggered relation in order to prevent liquid from passing upwardly therethrough. A baffle member 16, which is of larger crosssectional area than the pipe 14, is in alinement with and spaced from the lower end of the pipe 14. A conical member 17. covers the upper end of the pipe 14 and serves to direct downwardly into the gasometer 11 any liquid that may traverse the pipe 14.

The movable melnber 13 is provided wlth openings 18 which are covered by relatively thin members or diaphragms 19.

When the transformer or other ,electrical apparatus is placed in operation, the air enclosed in the space 4 is gradually deoxidized by the deoXidizer 5, substantially pure nitrogen remaining. Vhen the temperature wlthin the casing 1 varies by reason of changes in load or for other reasons, the volume of the oil varies with the changes in temperature to correspondingly vary the pressure of the gas. The gasometer 11 provides a convenient means for maintaining the pressure of the gas substantially constant within the limits corresponding to the capacity of the A gasometer.

When heavy overload conditions occur to cause the pressure within the tank to eX- ceed a predetermined safe value, the diaphragms 19 in the side walls of the movable member 13 which, under such conditions, occupies its uppermost position, are ruptured to permit escape of gases into the atmosphere. When'the overload conditions are relieved, the diaphragms may be replaced by the operator. The deoxidizer will again render inert the gas in the transformer.

In case short circuits occur between the windings of a transformer, the resultant arcs occurring beneath the surface of the oil cause the generation of gases in relatively great volume and a sudden increase in pressure within the casing. The gasometer substantially immediately assumes its expanded position and the diaphragms are ruptured to permit the escape of gases. It is probable also that a portion of the oil above the arcs will be thrown upwardly and will tend to escape through the opening' provided bythe ruptured diaphragms. ThebaHes 16 and 15 will operate to prevent substantially any oil from entering the gasometer. Such amount as may, however, traverse the pipe 14 will be deflected by the conical member 17 into the interior of the gasometer and thereby prevent it from escaping with the gases. Under ordinary circumstances, the space within the gasometer will be suiiicient to retain such oil as may pass the several baies.

Apparatus constructed in accordance with my invention will operate under normal con ditions to maintain a substantially constant pressure on the gases therein; that is, access of the gases'to the atmosphere is prevented during the usual temperature changes or during the expansion and contraction of the confined fluid. Means 'are provided, however, for escape of gases upon the occurrence of abnormal pressures and for preventing the escape of insulating oil with the gases.

I claim as my invention 1. The combination with a casing, of pressure-relieving means therefor comprising a gasometer communicating with said casing, and baliles interposed between said casing and said gasometer'.

2. The combination with a casin ,of a gasometer communicating therewit said gasometer having walls with portions that are weak relatively to the other portions for `yielding at a predetermined pressure within said gasometer.

3. The combination with a casing for containing an insulating fluid and having" an opening, of means for controlling the low of fluid through said opening, said means comprising a gasometer and a series of baffles adjacent to said opening.

4. Thecombination with a casing for electrical apparatus and means for maintaining inert gas therein, of means for maintainin the pressure of the gaseous contents of said casing substantially constant through a predetermined range of temperatures and for permitting said gas to escape into the atmosphere when the pressure reaches a predetermined value. v

5. The combination with a casing for electrical apparatus and deoxidizing means associated therewith for maintaining inert gas therein, of a gasometer communicating with said casing to permit variations in volume of said inert gas within predetermined limits, said gasometer having a diaphragm for rupturing at a predetermined pressure within said gasometer.

6. The combination with a casing for electrical apparatus and deoxidizing means associated therewith for maintaining inert as therein, of al gasometer vcommunicating with said casing to permit variations in volume of said inert gas within predetermined limits, said gasometer having a diaphragm for rupturing at a predetermined pressurewithin sa'id gasometen'and'a series of bales adjacent to said gasometer.

7. The combination with a casing for electrical apparatus and for containing an insulating uid, of deoxidizmg means associated therewith, said deoxidizing means being visible from the exterior of' said casing, and a gasometer communicating with said casing.

8. The combination with a casing for electrical apparatus and for containing an in- 1,567,580 i i Y 8' ,sulatin fluid, of deoxdiaing means assojacent to said gasometei for preventing the ciated t erewith, said deoxldlzlng means beentrance of said Huid into said gasometer.

ing Visible from `they exterior of said casing, In testimony whereof, I have hereunto 10 a gasometer communicating with said eassubscribed my name'this 22nd day of May,

5 ing and having a diaphragm to `be ruptured 1923.

when the pressure Within said casing eX- f ceeds a, predetermined value, and baes ady OTTO H. ESCHHOLZ. 

